JP2020055592A - Synthetic resin container - Google Patents

Abstract

To provide a synthetic resin container capable of sufficiently suppressing bulging of a container body part due to internal pressure while having a square cylindrical container shape.SOLUTION: A body part 4 of a container 1 has a polygonal cross-sectional shape, and is formed in a square cylindrical shape having a minimum body diameter part Dthat is gradually reduced in the diameter with respect to an upper end side and a lower end side of the body part 4. At least the minimum body diameter part Dis provided with a recessed groove part 40 formed along a circumferential direction. The cross-sectional shape of the portion where the recessed groove part 40 is formed is similar to the cross-sectional shape of the portion of the body part 4 that is formed in the square cylindrical shape, and each top part of the cross-sectional shape of the portion where the recessed groove part 40 is formed is located between the respective top parts of the cross-sectional shape of the portions of the body part 4 formed in the square cylindrical shape.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a synthetic resin container that can be used for applications such as carbonated beverages in which the contents after filling and sealing are positive pressure inside the container.

  Conventionally, a synthetic resin container obtained by forming a bottomed cylindrical preform using a thermoplastic resin such as polyethylene terephthalate, and then forming the preform into a bottle shape by biaxial stretch blow molding, etc. It is generally used in a wide field as a container containing various beverages, various seasonings and the like.

  This type of synthetic resin container is roughly classified into a container having a rectangular cylindrical shape called a square bottle and a container having a cylindrical shape called a round bottle. However, depending on the application, applicable container shapes have been limited. For example, in the case of containers used for carbonated drinks, since the inside of the container after filling and sealing the contents becomes positive pressure by carbon dioxide gas, the pressure is evenly dispersed and the shape is extremely uneven. Usually, the shape of the container is cylindrical so as not to be deformed (see, for example, Patent Document 1).

  On the other hand, a rectangular bottle having a rectangular cylindrical container shape has advantages such as good storage efficiency when packed in a box for transport, and good space efficiency when displayed at a store. For this reason, for example, in Patent Literature 2, an annular reinforcing rib is formed on a container body formed in a rectangular cylindrical shape so that a rectangular bottle can be used for a carbonated beverage application, so that the container can be made to have an internal pressure. Attempts have been made to suppress bulging of the torso.

However, the swelling of the container body due to the internal pressure cannot be sufficiently suppressed only by forming the annular reinforcing rib as in Patent Document 2.
Generally, after the contents of the container are filled and sealed, the container body is wrapped with a label indicating the contents and supplied to the market. For this reason, if the swelling of the container body due to the internal pressure is not sufficiently suppressed, not only is it difficult to store the container in a carton, but also there is a problem that the label is rubbed by the vibration during transportation and damaged. is there.

  In addition, in recent years, where the use of this type of synthetic resin container has become more common in a wide range of fields, it is necessary to differentiate it from other products and enhance product appeal. It has been demanded. If a rectangular cylindrical container shape can be applied to a container containing a carbonated beverage or the like whose content has been limited to a conventionally applicable container shape, it will be possible to enhance product appeal by diversifying designs.

  In view of the above, the inventors of the present invention have proposed a synthetic resin container in Patent Literature 3, which has a rectangular cylindrical container shape and can sufficiently suppress swelling of the container body due to internal pressure.

JP-A-10-264917 JP 2008-7147 A JP 2018-2293 A

  The present inventors have conducted intensive studies so as to more effectively suppress the swelling of the container body due to the internal pressure in order to further improve the pressure resistance performance, and as a result, have completed the present invention.

  The synthetic resin container according to the present invention includes a mouth portion, a shoulder portion, a body portion, and a bottom portion, and the body portion has a polygonal cross-sectional shape, and is provided on an upper end side and a lower end side of the body portion. In addition to being formed in a rectangular cylindrical shape having a minimum body diameter portion gradually reduced in diameter, at least the minimum body diameter portion is provided with a groove formed along the circumferential direction, The cross-sectional shape of the portion where the groove is formed is similar to the cross-sectional shape of the portion formed in the shape of the rectangular tube of the body, and each apex of the cross-sectional shape of the portion where the concave groove is formed is It is configured such that it is located between the respective tops of the cross-sectional shape of the rectangular tube-shaped portion of the body.

  ADVANTAGE OF THE INVENTION According to this invention, the synthetic resin container which the deformation | transformation by the expansion | swelling of a trunk | drum by internal pressure was suppressed effectively while having the container shape which the cross-sectional shape of the container trunk | drum was made polygonal is provided.

It is a perspective view showing the outline of the synthetic resin container concerning a first embodiment of the present invention. It is a front view showing the outline of the synthetic resin container concerning a first embodiment of the present invention. It is a diagonal side view which shows the outline of the synthetic resin container which concerns on 1st embodiment of this invention from the diagonal direction of 45 degrees with respect to the front. It is a top view showing the outline of the synthetic resin container concerning a first embodiment of the present invention. It is a bottom view showing the outline of the container made of synthetic resin concerning a first embodiment of the present invention. FIG. 3 is an AA end view of FIG. 2. FIG. 3 is a BB end view of FIG. 2. FIG. 3 is an explanatory diagram showing an AA end view of FIG. 2 and a BB end view of FIG. 2 in an overlapping manner. FIG. 3 is a CC end view of FIG. 2. FIG. 4 is a DD end view of FIG. 3. It is a perspective view showing the outline of the container made of synthetic resin concerning a second embodiment of the present invention. It is a front view showing the outline of the synthetic resin container concerning a second embodiment of the present invention. It is a diagonal side view which shows the outline of the synthetic resin container which concerns on 2nd embodiment of this invention from the direction of diagonal 22.5 degrees with respect to a front. It is a top view showing the outline of the synthetic resin container concerning a second embodiment of the present invention. It is a bottom view showing the outline of the synthetic resin container concerning a second embodiment of the present invention. It is EE end elevation of FIG. It is FF end elevation of FIG. It is explanatory drawing which shows the cross-sectional shape of the container body part of the prior art example. It is explanatory drawing which shows the cross-sectional shape of the container body part of other conventional examples corresponding to FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
First, a first embodiment of the present invention will be described.
FIG. 1 is a perspective view showing the synthetic resin container according to the present embodiment as viewed obliquely from above, FIG. 2 is a front view, and FIG. FIG. 4 is a plan view, and FIG. 5 is a bottom view.
6 is an AA end view of FIG. 2, FIG. 7 is a BB end view of FIG. 2, FIG. 8 is an AA end view of FIG. 2, and a BB end view of FIG. 9 is an end view taken along the line CC in FIG. 2, and FIG. 10 is an end view taken along the line DD in FIG. 3. In these end views, the thickness of the container 1 is omitted. I have.

  The container 1 includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5, and the container 1 shown in the drawing is generally referred to as a square bottle in which the body portion 4 is formed in a rectangular cylindrical shape. It has a container shape.

  Such a container 1 is formed by molding a bottomed cylindrical preform by injection molding or compression molding using a thermoplastic resin, and molding the preform into a predetermined container shape by biaxial stretch blow molding or the like. Manufactured by

  In manufacturing the container 1, as the thermoplastic resin to be used, any blow-moldable resin can be used. Specifically, thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, amorphous polyarylate, polylactic acid, and copolymers thereof, and those blended with these resins or other resins are preferable. It is. In particular, an ethylene terephthalate-based thermoplastic polyester such as polyethylene terephthalate is preferably used. Further, polycarbonate, acrylonitrile resin, polypropylene, propylene-ethylene copolymer, polyethylene and the like can also be used.

The mouth 2 is a cylindrical portion serving as an outlet for taking out contents, and a lid (not shown) for sealing the inside of the container is attached to the mouth 2.
In addition, the lower end of the mouth 2 is connected to a shoulder 3 that expands in diameter toward the body 4 and connects the mouth 2 and the body 4. In the illustrated example, the shoulder 3 is a pyramid. It is formed in a trapezoidal shape.

  The body portion 4 is a portion occupying most of the height direction of the container 1, and has an upper end connected to the shoulder portion 3 and a lower end connected to the bottom portion 5. In the example shown in the figure, the plurality of legs 50 are rotationally symmetric about the central axis and radially at equal intervals so that the self-standing stability is not impaired even if the pressure in the container becomes positive. Although the shape is arranged, the shape of the bottom 5 is not particularly limited as long as the container 1 can stand alone after filling and sealing the contents.

  Here, the height direction refers to a direction perpendicular to the horizontal plane when the container 1 is erected on a horizontal plane with the mouth 2 up, and in this state, the vertical, horizontal, and vertical directions of the container 1 Shall be stipulated.

In the present embodiment, the transverse cross-sectional shape (shape of a cross section orthogonal to the height direction) of the body 4 is a square shape with rounded corners.
Further, the body 4 gradually decreases in diameter toward the center in the height direction with respect to the upper end and the lower end thereof, so that its contour becomes convex toward the inside of the container along the height direction. It is formed in the shape of a gently curved rectangular tube, and the center in the height direction of the body 4 is the smallest body diameter _Dmin with the smallest diameter. In addition, the trunk portion 4 formed in such a rectangular tubular shape is provided with a concave groove portion 40 formed along the circumferential direction, and in the illustrated example, is provided in the minimum trunk diameter portion _Dmin . The concave groove portion 40, the two concave groove portions 40 provided above the concave groove portion 40, and the two concave groove portions 40 provided below the concave groove portion 40 are provided at equal intervals along the height direction.

FIG. 8 shows the cross-sectional shape of the rectangular tube-shaped portion of the body 4 of the container 1 (see FIG. 6) and the cross-sectional shape of the portion where the concave groove portion 40 is formed (see FIG. 7). ), The groove 40 formed in the body 4 has a cross-sectional shape of a portion where the groove 40 is formed and a cross-section of a portion of the body 4 formed in a rectangular tube shape. It is formed to resemble the shape.
6, 7, and 8, for convenience of description, the scale of the cross-sectional shape of the portion of the body 4 formed in the shape of a square tube and the scale of the cross-sectional shape of the portion of the body 4 where the concave groove 40 is formed are changed. ing.

  Here, "similar" means not only "similarity" in a narrow sense in mathematics, but also means that the shapes are similar to each other. Therefore, the cross-sectional shape of the portion where the concave groove portion 40 is formed can be recognized as the same polygonal shape having the same number of sides and the same number of tops as the cross-sectional shape of the portion of the body portion 4 formed into a rectangular tube shape. What is necessary is just to be similar to the degree.

  For example, when the body 4 is formed in a square tube shape having a square cross section, the cross section of the portion where the concave groove 40 is formed is also made to be square. Alternatively, as long as the original shape can be recognized as a square shape, each side of the cross-sectional shape of the portion where the concave groove portion 40 is formed may be curved as illustrated. Furthermore, each corner of the cross-sectional shape of the portion where the concave groove portion 40 is formed is chamfered in a C-chamfered shape, or a vertex having an R-chamfer is further chamfered in a straight line, so that the side surface and the It may be formed to include one surface.

  Further, in forming the concave groove portion 40, in addition to the above, in addition to the above, each top of the cross sectional shape of the portion where the concave groove portion 40 is formed is the cross sectional shape of the rectangular cylindrical portion of the body portion 4. The concave groove portion 40 is formed so as to be located between the respective top portions, preferably at the center in the lateral width direction of the side surface of the body portion 4 (see FIG. 8).

  The groove 40 thus formed is recessed so as to cross each corner of the body 4 and has a groove bottom extending in a direction orthogonal to the height direction. As shown by the one-dot chain line in FIG. 10, the imaginary line connecting the groove bottoms of the concave grooves 40 along the height direction is gently curved along the height direction so that the virtual line is substantially parallel to the contour of the body 4. Preferably.

  According to the present embodiment, by forming such a concave groove portion 40 in the body portion 4 of the container 1 having a rectangular cylindrical container shape, the swelling of the body portion 4 can be achieved even if the inside of the container becomes a positive pressure. Can be effectively suppressed. The reason will be described in comparison with a conventional example.

  When the inside of the container becomes a positive pressure, the rectangular bottle having a square cross-sectional shape of the body tends to be deformed so that the side of the body swells outwardly of the container as shown in FIG. While the force acts, a force acts on the corner of the body to deform the corner so as to be drawn into the container. As a result, the rectangular bottle is deformed by the action of these forces so that the cross section of the body becomes circular.

  Further, as in Patent Literature 2, when annular reinforcing ribs are formed on the body of a rectangular bottle having a square cross-sectional shape, the cross-sectional shape of the portion where the annular reinforcing ribs are formed is circular. Shape. For this reason, when the inside of the container becomes a positive pressure, the portion where the annular reinforcing ribs are formed hardly swells outward from the container because the internal pressure (force) acts uniformly on the entire reinforcing ribs. On the other hand, in the case of a body having a square cross-sectional shape, when an internal pressure (force) that deforms so as to swell outside the container acts, the side surface easily swells and deforms, and the corners are drawn into the container. Due to the deformation, the square shape of the body of the square bottle cannot be maintained (see FIG. 19).

  On the other hand, in the present embodiment, when the inside of the container becomes a positive pressure, a force for deforming the groove bottom 40 so as to expand outwardly of the container acts on the groove bottom, and the concave groove 40 is formed. At the top of 40, a force acts to draw the container inward. In FIG. 8, the directions of the respective forces are indicated by arrows, and by the action of these forces, the force for deforming the corners of the body 4 so as to be drawn into the container and the side surface of the body 4 Both of the forces for deforming so as to bulge outward from the container are offset, and as a result, deformation due to bulging of the body 4 can be suppressed.

And the trunk | drum 4 is formed in the square cylindrical shape which has the minimum trunk | drum diameter part _Dmin gradually reduced in diameter with respect to the upper end side and the lower end side of the trunk | drum 4 made into substantially the same diameter, and at least. By providing the concave groove portion 40 in the minimum diameter reducing portion _Dmin , the deformation due to the bulging of the body portion 4 can be more effectively suppressed.
At this time, the width W _{0 of} the minimum body diameter portion D _min when viewed from the front is reduced to 60 to 99% of the width W of the maximum body diameter portion on the upper end side and the lower end side of the body portion 4. Is preferred.

[Second embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 11 is a perspective view showing the synthetic resin container according to the present embodiment obliquely from above, FIG. 12 is a front view, and FIG. 14 is a plan view, and FIG. 15 is a bottom view.
FIG. 16 is an EE end view of FIG. 12, and FIG. 17 is an FF end view of FIG. 13. In these end views, the thickness of the container 1 is omitted.

  The container 1 in the present embodiment has the same configuration as the first embodiment except that the cross-sectional shape of the body 4 is octagonal. The description of the operation will be omitted.

Also in the present embodiment, when the inside of the container becomes a positive pressure, the force acting on the portion where the concave groove portion 40 is formed causes the force acting on the portion of the body portion 4 formed in the rectangular tube shape. Due to the cancellation, deformation due to the bulging of the trunk 4 can be suppressed. And the trunk | drum 4 is formed in the square cylindrical shape which has the minimum trunk | drum diameter part _Dmin gradually reduced in diameter with respect to the upper end side and the lower end side of the trunk | drum 4 made into substantially the same diameter, and at least. By providing the concave groove portion 40 in the minimum diameter reducing portion _Dmin , the deformation due to the bulging of the body portion 4 can be more effectively suppressed.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

[Example 1]
As a first embodiment, the container 1 shown in FIG. 1 and the like was filled and sealed with carbonated water so that the pressure in the container was 0.27 MPa under a temperature condition of 22 ° C.
The height H of the container 1 before filling and sealing with carbonated water is 206 mm, the width W ₀ of the minimum body diameter portion D _min provided with the concave groove 40 is 55.34 mm, and the diagonal width D ₀ is 63.70 mm. The width W of the maximum body diameter was 59.80 mm.
Also, radial contraction rate of the width W ₀ of the smallest cylinder diameter D _min for the width W of the maximum cylinder diameter was 93%.

When the container 1 filled with and sealed with carbonated water was allowed to stand for 24 hours in a constant temperature bath at a set temperature of 22 ° C. and measured for 24 hours, the width W ₀ of the minimum body diameter D _min was 55.48 mm, and the diagonal width D ₀ was 63. 0.86 mm, the width W of the largest waist portion has changed to 60.28 mm, the width W ₀ of the smallest waist portion D _min has increased by 0.25%, and the diagonal width D ₀ has increased by 0.25%. , radial contraction rate of the width W ₀ of the smallest cylinder diameter D _min for the width W of the maximum cylinder diameter is 92%, was largely maintain the original shape of the container.

[Example 2]
The dimensions after standing for 24 hours were measured in the same manner as in Example 1 except that the set temperature of the thermostat was set to the set temperature of 37 ° C., and the width W ₀ of the minimum body diameter portion D _min was 55.53 mm. The angular width D ₀ has changed to 63.92 mm, the width W of the maximum body diameter portion has changed to 60.61 mm, the width W ₀ of the minimum body diameter portion D _min is 0.34%, and the diagonal width D ₀ is 0. despite increased 0.35%, radial contraction rate of the width W ₀ of the smallest cylinder diameter D _min for the width W of the maximum cylinder diameter is 92%, was largely maintain the original shape of the container.

[Example 3]
As a second embodiment, the container 1 shown in FIG. 10 and the like was filled with carbonated water so that the pressure in the container became 0.27 MPa under a temperature condition of 22 ° C., and sealed.
The height H of the container 1 before filling and sealing with carbonated water is 206 mm, the width W ₀ of the minimum body diameter portion D _min provided with the concave groove portion 40 is 55.43 mm, and the diagonal width D ₀ is 51.68 mm. The width W of the maximum body diameter was 60.13 mm.
Also, radial contraction rate of the width W ₀ of the smallest cylinder diameter D _min for the width W of the maximum cylinder diameter was 92%.

When the container 1 filled with and sealed with carbonated water was allowed to stand for 24 hours in a constant temperature bath at a set temperature of 22 ° C., the measurement was performed. As a result, the width W ₀ of the minimum body diameter D _min was 55.71 mm, and the diagonal width D ₀ was 53. 0.23 mm, the width W of the maximum body diameter portion has changed to 63.36 mm, the width W ₀ of the minimum body diameter portion has increased by 0.51%, and the diagonal width D ₀ has increased by 3.00%. radial contraction rate of the width W ₀ of the smallest cylinder diameter D _min for the width W of the trunk diameter is 88%, was largely maintain the original shape of the container.
[Example 4]
When the dimensions after standing for 24 hours were measured in the same manner as in Example 3 except that the set temperature of the thermostat was set to the set temperature of 37 ° C., the width W ₀ of the minimum body diameter portion D _min was 55.86 mm, The angular width D ₀ is changed to 54.19 mm, the width W of the maximum body diameter portion is changed to 63.67 mm, the width W ₀ of the minimum body diameter portion D _min is 0.78%, and the diagonal width D ₀ is 4 despite increased .86%, radial contraction rate of the width W ₀ of the smallest cylinder diameter D _min for the width W of the maximum cylinder diameter is 88%, was largely maintain the original shape of the container.

[Comparative Example 1]
Using the same container as in Example 1 except that the body portion 4 was not reduced in diameter and the outline thereof was linear along the height direction, the pressure in the container under a temperature condition of 22 ° C. Carbonated water was filled to 0.27 MPa and sealed.
The height H of the container 1 before filling and sealing with carbonated water was 206 mm, the width of the body was 60.39 mm, and the diagonal width was 71.08.

  After measuring the container 1 filled with carbonated water and sealed in a constant temperature bath at a set temperature of 22 ° C. for 24 hours, the width of the body changed to 61.01 mm, and the diagonal width changed to 71.22 mm. The width of the torso was increased by 1.02% and the diagonal width was increased by 0.20%.

[Comparative Example 2]
When the dimensions after standing for 24 hours were measured in the same manner as in Comparative Example 1 except that the set temperature of the constant temperature bath was set to the set temperature of 37 ° C., the width of the trunk was 61.28 mm, and the diagonal width was 71.24 mm. The width of the trunk increased by 1.47% and the diagonal width increased by 0.23%.

  As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made within the scope of the present invention. Nor.

For example, in the above-described embodiment, the five concave grooves 40 are arranged side by side at equal intervals along the height direction, but the groove width of the concave grooves 40 is varied according to the position where the concave grooves 40 are formed. Alternatively, the intervals of juxtaposition may be different. Further, the number of the concave grooves 40 is not limited, and it is sufficient that the concave grooves 40 are provided at least in the minimum body diameter portion _Dmin .

Further, in the above-described embodiment, the central portion in the height direction of the trunk portion 4 is set to the minimum trunk diameter portion _Dmin , but is not limited thereto.

  In the first embodiment described above, the cross section of the trunk 4 is square, and in the second embodiment, the cross section of the trunk 4 is octagonal. The surface shape can be formed in the shape of an n-sided prism (where n is 3 to 12).

  Further, the synthetic resin container according to the present invention can be used not only for carbonated beverages but also for applications in which, for example, nitrogen gas or the like is sealed together with contents and the inside of the container becomes positive pressure. Needless to say.

  INDUSTRIAL APPLICABILITY The container made of a synthetic resin according to the present invention can be used for applications such as for carbonated beverages in which the contents after filling and sealing are positive pressure.

DESCRIPTION OF SYMBOLS 1 Container 2 Mouth part 3 Shoulder part 4 Body part 40 Groove part 5 Bottom part D _min minimum body diameter part

Claims (1)

Mouth, shoulder, torso, and bottom,
The body has a polygonal cross-sectional shape, and is formed in a rectangular cylindrical shape having a minimum body diameter portion gradually reduced in diameter with respect to an upper end side and a lower end side of the body portion,
At least in the minimum body diameter portion, a concave groove formed along the circumferential direction is provided,
The cross-sectional shape of the portion where the concave groove portion is formed is similar to the cross-sectional shape of the portion formed in the shape of the rectangular cylinder of the body portion, and the cross-sectional shape of the portion where the concave groove portion is formed. A synthetic resin container characterized in that a top portion is located between the top portions of a cross section of a portion of the body portion formed in a rectangular tube shape.